Welcome back to the O.C, Mischa Barton.

MTV announced that the actress is joining the cast of its revival of "The Hills." She joins the reality show's original stars Heidi Montag, Spencer Pratt, Audrina Patridge, Jason Wahler, Frankie Delgado, Justin Bobby Brescia, Stephanie Pratt, Brody Jenner and Whitney Port.

It's a very meta move for "The Hills." Barton starred on the teen drama "The O.C.," which helped inspire MTV's teen reality series "Laguna Beach: The Real Orange County." The success of that show led to the spinoff "The Hills."

"The Hills: New Beginnings" was announced in August after cast members reunited on the red carpet at the MTV Video Music Awards. It will reunite original cast members, alongside their children, friends and some new faces, and follow their personal and professional lives while living in Los Angeles.

There's been speculation that the show would add some new faces, since "The Hills" leads Lauren Conrad and Kristin Cavallari declined to return. The latter is starring on her own reality series, "Very Cavallari," on E!